Stainless Steel Coil Tube — Single-Well Coil Furnace Redesign Application
Product Overview
The Stainless Steel Coil Tube (Product No. 1127) is a precision-engineered continuous or coiled tube product manufactured by Wenzhou Jixing Metal Materials Co., Ltd, specifically designed for use in single-well coil furnace systems and related thermal processing applications. This product represents an advanced iteration of coil tube technology, incorporating lessons learned from the redesign and optimization of single-well coil furnaces (单井盘管炉改造设计). The coil tube is engineered to deliver superior thermal efficiency, mechanical durability, and extended service life under demanding industrial conditions.
Unlike conventional straight-seam or welded tubes, the coil tube is formed through a continuous coiling process that eliminates longitudinal weld seams, thereby enhancing structural integrity and reducing the risk of thermal fatigue failure at joint locations. This makes the product particularly suitable for applications involving cyclic thermal loading, high-temperature exposure, and fluid transport under pressure.
Material & Properties
Base Material Composition
The coil tube is fabricated from high-grade austenitic stainless steel, with typical grade options including:
- 304 / 304L (UNS S30400 / S30403) — General-purpose austenitic stainless steel with excellent corrosion resistance and formability.
- 316 / 316L (UNS S31600 / S31603) — Molybdenum-enhanced grade offering superior resistance to pitting and crevice corrosion in chloride environments.
- 321 (UNS S32100) — Titanium-stabilized grade providing enhanced resistance to sensitization at elevated temperatures (up to 870°C / 1598°F).
- 310S (UNS S31008) — High-temperature austenitic grade suitable for sustained service up to 1150°C (2100°F) with excellent oxidation resistance.
Key Mechanical and Thermal Properties
- Tensile Strength (抗拉强度): ≥ 520 MPa (75 ksi) minimum, typical range 550–700 MPa depending on grade and heat treatment.
- Yield Strength (屈服强度): ≥ 205 MPa (29.7 ksi) at 0.2% offset.
- Elongation (延伸率): ≥ 35% at break (A50mm), ensuring excellent ductility for forming and bending operations.
- Thermal Conductivity (热导率): 14–16 W/(m·K) at 100°C, providing controlled heat transfer characteristics.
- Thermal Expansion Coefficient (热膨胀系数): 16–18 × 10⁻⁶ /K (20–100°C range).
- Maximum Service Temperature (最高使用温度): Up to 870°C (1598°F) for 321 grade; up to 1150°C (2100°F) for 310S grade.
- Corrosion Resistance (耐腐蚀性): Excellent resistance to atmospheric, aqueous, and chemical environments; superior performance in reducing and oxidizing acids.
Specifications
| Parameter | Specification | Standard Reference |
|---|---|---|
| Product Name | Stainless Steel Coil Tube (盘管 Coiltube) | — |
| Product Number | 1127 | — |
| Manufacturer | Wenzhou Jixing Metal Materials Co., Ltd | — |
| Outer Diameter (外径) | 6.0 mm – 50.8 mm (0.25" – 2.0") | ASTM A213 / A269 |
| Wall Thickness (壁厚) | 0.5 mm – 3.0 mm (0.020" – 0.118") | ASTM A213 / A269 |
| Coil Diameter (盘管直径) | 300 mm – 2000 mm (12" – 80") | Custom configuration |
| Coil Length (盘管长度) | Up to 5000 m per coil (configurable) | — |
| Surface Finish (表面状态) | 2B, BA (Bright Annealed), Pickled & Passivated | ASTM A403 |
| Tolerance — OD (外径公差) | ±0.05 mm (for OD ≤ 12.7 mm); ±0.10 mm (for OD > 12.7 mm) | ASTM A213 |
| Tolerance — Wall Thickness (壁厚公差) | ±10% of nominal | ASTM A213 |
| Applicable Grades (适用牌号) | 304, 304L, 316, 316L, 321, 310S | ASTM A213 / A269 |
| Heat Treatment (热处理) | Solution Annealed (固溶退火), 1010–1150°C followed by water quench | ASTM A403 |
| Applicable Standards (适用标准) | ASTM A213, ASTM A269, ASME SA-213, GB/T 12771, JIS G3459 | — |
| Pressure Rating (压力等级) | Up to 40 MPa (5800 psi) depending on diameter and wall thickness | ASME B31.3 |
Manufacturing Process
1. Raw Material Selection and Incoming Inspection
High-purity stainless steel strip or seamless tube blank material is sourced from certified mill suppliers. Incoming inspection includes spectroscopic composition analysis (光谱成分分析) to verify chemical composition conformity with the specified grade requirements, along with mechanical property verification through tensile testing.
2. Precision Cold Drawing (精密冷拔)
The tube blank undergoes cold drawing through a series of precision-diameter die sets to achieve the target outer diameter and wall thickness with tight dimensional tolerances. This process enhances grain structure alignment, improves surface finish, and increases mechanical strength through work hardening (加工硬化).
3. Solution Annealing (固溶退火)
The cold-worked tube is heated to 1010–1150°C in a protective atmosphere furnace (氩气保护炉) to dissolve carbide precipitates and restore full austenitic microstructure. Rapid water quenching follows to lock in the desired mechanical properties and prevent sensitization (敏化).
4. Surface Treatment (表面处理)
The annealed tube receives pickling and passivation (酸洗钝化) treatment to remove oxide scale and form a protective chromium oxide passive layer (铬氧化钝化层). For applications requiring superior surface aesthetics and corrosion resistance, Bright Annealing (光亮退火, BA) is performed in a controlled hydrogen atmosphere.
5. Continuous Coiling (连续盘绕)
The processed tube is coiled onto precision-engineered mandrels using a computer-controlled winding system that ensures uniform coil diameter, consistent inter-coil spacing, and controlled winding tension. This eliminates the risk of surface damage, kinking, or geometric distortion that can occur during manual coiling.
6. Final Quality Inspection (最终质量检验)
Each coil undergoes comprehensive final inspection including:
- Dimensional Verification (尺寸验证): Optical and contact measurement of OD, wall thickness, and coil diameter.
- Visual Inspection (目视检查): Surface quality assessment for defects, discoloration, or mechanical damage.
- Hydrostatic Pressure Testing (水压试验): Internal pressure testing at 1.5× the maximum design pressure to verify weld integrity and structural soundness.
- Corrosion Testing (腐蚀测试): Salt spray testing (ASTM B117) and intergranular corrosion testing (ASTM A262) as required.
Applications
The Stainless Steel Coil Tube (Product No. 1127) is engineered for a diverse range of industrial applications, with particular emphasis on thermal processing systems informed by the single-well coil furnace redesign experience:
Primary Applications
- Single-Well Coil Furnace Systems (单井盘管炉系统): Serves as the primary heat exchange element in single-well coil furnaces used for continuous heat treatment of metal products. The coil tube's seamless construction and superior thermal fatigue resistance make it ideal for the cyclic thermal loading conditions inherent in furnace operation.
- Heat Exchangers (换热器): Used in shell-and-tube and plate heat exchanger assemblies for chemical processing, oil and gas, and power generation applications.
- Boiler and Steam Systems (锅炉及蒸汽系统): Employed in low- and medium-pressure boiler tubes, superheaters, and economizer coils where corrosion resistance and thermal stability are critical.
- Chemical Processing (化工处理): Transport and processing of corrosive fluids, acids, and solvents in pharmaceutical, food and beverage, and petrochemical industries.
- Gas Fired Heating (燃气加热): Fuel gas supply lines and burner manifold coils in industrial heating applications.
Industry Sectors
- Petrochemical and Refining (石油化工)
- Pharmaceutical Manufacturing (制药)
- Food and Beverage Processing (食品饮料加工)
- Power Generation (发电)
- Automotive Component Heat Treatment (汽车零部件热处理)
- Semiconductor Manufacturing Equipment (半导体制造设备)
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd maintains rigorous quality management systems and holds the following certifications and compliance standards:
- ISO 9001:2015 — Quality Management System certification ensuring consistent product quality and process control throughout the manufacturing chain.
- ISO 14001:2015 — Environmental Management System certification demonstrating commitment to environmentally responsible manufacturing practices.
- ISO 45001:2018 — Occupational Health and Safety Management System certification.
- ASTM Compliance — Products manufactured in accordance with ASTM A213, A269, A403, and related specifications.
- ASME Stamp — Where applicable, products manufactured under ASME SA-213 code requirements for pressure-containing applications.
- CE Marking — Conformity with European directives for products intended for the European Economic Area market.
- Mill Test Reports (MTR, 材质证明书) — Comprehensive material test reports provided with each shipment, including chemical analysis, mechanical test results, and heat treatment documentation.
Unique Selling Points
- Seamless Construction (无缝结构): Eliminates longitudinal weld seams, significantly reducing the risk of thermal fatigue cracking and corrosion initiation at joint locations — a critical advantage for single-well coil furnace applications subject to repeated thermal cycling.
- Redesign-Optimized Geometry (改造优化几何设计): Coil geometry and tube specifications are informed by lessons learned from single-well coil furnace redesign projects, incorporating improved heat transfer coefficients and reduced thermal stress concentrations.
- Extended Service Life (延长使用寿命): Superior resistance to thermal fatigue, oxidation, and corrosion extends the operational lifespan of furnace coil assemblies, reducing downtime and replacement frequency.
- Custom Configuration Capability (定制化配置能力): Flexible coil diameter, tube specification, and grade selection to match specific furnace design requirements and operating conditions.
- Full Traceability (完整可追溯性): Each coil is traceable to its raw material mill heat number, with complete documentation of all manufacturing and inspection steps.
Note: The technical specifications and performance characteristics described in this document are based on the product knowledge base of Wenzhou Jixing Metal Materials Co., Ltd (Product No. 1127). For project-specific applications, particularly those involving extreme temperature, pressure, or corrosive environments, it is recommended to consult the manufacturer directly for a tailored engineering assessment and specification confirmation.